Intel Xeon X3440 BX80605X3440 User Manual

Thermal/Mechanical Specifications and Design Guidelines

77

If the boxed processor fan heatsink 4-pin connector is connected to a 3-pin 
motherboard header, it will operate as follows:

The boxed processor fan will operate at different speeds over a short range of internal 
chassis temperatures. This allows the processor fan to operate at a lower speed and 
noise level, while internal chassis temperatures are low. If internal chassis temperature 
increases beyond a lower set point, the fan speed will rise linearly with the internal 
temperature until the higher set point is reached. At that point, the fan speed is at its 
maximum. As fan speed increases, so do fan noise levels. Systems should be designed 
to provide adequate air around the boxed processor fan heatsink that remains cooler 
then lower set point. These set points, represented in 

vary by a few degrees from fan heatsink to fan heatsink. The internal chassis 
temperature should be kept below 40 ºC. Meeting the processor's temperature 
specification (see 

) is the responsibility of the system integrator.

The motherboard must supply a constant +12 V to the processor's power header to 
ensure proper operation of the variable speed fan for the boxed processor. Refer to 

 for the specific requirements.

1.

Set point variance is approximately ± 1 ° C from fan heatsink to fan heatsink.

º

X ≤ 30

When the internal chassis temperature is below or equal to this set point, 

the fan operates at its lowest speed. Recommended maximum internal 

chassis temperature for nominal operating environment.

Y = 35

When the internal chassis temperature is at this point, the fan operates 

between its lowest and highest speeds. Recommended maximum internal 

chassis temperature for worst-case operating environment.

-

Z ≥ 40

When the internal chassis temperature is above or equal to this set point, 

the fan operates at its highest speed.

-